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Stereo Crosstalk Elimination (reduction) Par Excellence!

Sorry if I'm missing the point, but I though it was only applied to the opposite ear! It just has to be done over and over again because both ears pick up the correcting signal, unless a local wearable device was used right at each ear to correct the crosstalk. But in this case, if it worked perfectly, then still the opposite ear would hear nothing from that channel, so it'd just be simpler because the correction signal would not have to be recursive. I still think we have to find a way to reduce the effect as sounds are panned further left or right.
Ideally, that would be the case, but in reality, it doesn’t work that way.
The sound comes from the left speaker, and the left ear hears it first. Then, after the ITD, the right ear hears it.
At this point, the right speaker sends out a cancellation signal for it. While this signal cancels the sound for the right ear, the left ear also hears the cancellation signal.
That’s why repeated signals are cross-fed to erase unintended traces.
The graph I shared shows the results of applying a filter that specifically targets only the opposite ear. (Of course, this isn’t possible in reality.)

similar to what Dolby Pro-Logic up-mixing does.
This is a bit off-topic, but I have almost implemented Dolby Pro Logic IIX using EQ APO (excluding dynamic steering, as EQ APO cannot utilize real-time level detection to assign weights, so it would need to be re-created in Reaper).
While working on this, I also started studying Logic7, which many people seemed to appreciate.
I recall reading some documents about the Lexicon DC-1 and noticing that it also had a form of crosstalk cancellation hidden within it.

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Ideally, that would be the case, but in reality, it doesn’t work that way.
The sound comes from the left speaker, and the left ear hears it first. Then, after the ITD, the right ear hears it.
At this point, the right speaker sends out a cancellation signal for it. While this signal cancels the sound for the right ear, the left ear also hears the cancellation signal.
That’s why repeated signals are cross-fed to erase unintended traces.
The graph I shared shows the results of applying a filter that specifically targets only the opposite ear. (Of course, this isn’t possible in reality.)


This is a bit off-topic, but I have almost implemented Dolby Pro Logic IIX using EQ APO (excluding dynamic steering, as EQ APO cannot utilize real-time level detection to assign weights, so it would need to be re-created in Reaper).
While working on this, I also started studying Logic7, which many people seemed to appreciate.
I recall reading some documents about the Lexicon DC-1 and noticing that it also had a form of crosstalk cancellation hidden within it.

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That angular dependence issue is something I've played with, so that's also something that could be much more easily worked on with STC, maximizing the crosstalk below 700 Hz. This can also be done by placing drivers further apart at lower frequencies. But then there are new perceptual issues that arise. I have read that people have tried using wider low frequency spacing along with STC for each speaker spacing, and reported excellent results. For just walking around the room listening, it's best to have location coherency down to at least 100 Hz. Probably 80 Hz.
 
That angular dependence issue is something I've played with, so that's also something that could be much more easily worked on with STC, maximizing the crosstalk below 700 Hz. This can also be done by placing drivers further apart at lower frequencies. But then there are new perceptual issues that arise. I have read that people have tried using wider low frequency spacing along with STC for each speaker spacing, and reported excellent results. For just walking around the room listening, it's best to have location coherency down to at least 100 Hz. Probably 80 Hz.
The steering I mentioned refers to the steering found in upmixers.
Rather than using fixed angles, it extracts the volume differences and directional information from the L and R channels of the audio source. Based on this, the mixing coefficients dynamically change, allowing real-time adjustments to the weights and altering the angles accordingly.

In EQ APO, this is not possible, as only fixed angles can be used. Logic7, in particular, seemed to make more active use of such rear-angle processing.

Additionally, utilizing decorrelation below 700 Hz could provide quite an interesting experience.
I apply this in my custom upmixing code and artificial reverb as well, so feel free to give it a try. I'll send you a PM.
 
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